Preoperative CT Scans Prior to Distal Tibial Intramedullary Nailing Do not Change Treatment Decisions or Surgical Outcomes.

Introduction: Distal tibia shaft fractures have a high association with posterior malleolar fractures (PMFs); hence, a preoperative ankle CT scan is commonly obtained. The purpose of this study was to determine whether a CT scan for distal third tibia shaft fractures is associated with differences in recognition of a posterior malleolus fracture (PMF), treatment of an identified PMF, outcomes, and postoperative complications.

Methods: We retrospectively reviewed cases of adult patients with distal third tibia shaft fractures treated with an intramedullary nail between 2018 and 2020. Patients were divided into 2 groups based on whether they received a preoperative ankle CT scan. Outcomes included surgical time, the rate of missed PMFs or postoperative PMF displacement, the treatment of the PMFs, postoperative weight-bearing restrictions, Patient-Reported Outcomes Measurement Information System Global-10 (PROMIS Global-10) scores, and unplanned revision surgeries.

Results: 124 patients (age 45 ± 18 years; 39.5% female) with distal third tibia shaft fractures treated with intramedullary nailing and with minimum 6 months of follow-up were reviewed. 26 patients received preoperative CT scans, and 98 patients did not have CT scans. The rate of detected PMF was 69.2% (N = 18) in patients with CT and 55.1% (N = 54) in patients without CT (P = 0.19). No significant differences were observed in all outcomes between the 2 groups (P > 0.05). 3 PMFs not visible on radiographs were identified on CT, and they did not require fixation and did not displace. PMFs that were greater than one-third of the joint surface were more likely to have a preoperative CT (P < 0.01).

Discussion: Preoperative CT scans for distal third tibia shaft fractures may be useful in characterizing large PMFs; however, this knowledge does not translate into shorter surgical time, increased fixation rates, decreased unplanned revision surgery, or improved patient-reported outcomes. Discovery of PMFs did not always lead to fixation, and PMFs without fixation did not become further displaced.